The Battle of Fort Sanders was fought on November 29, 1863 near Knoxville, Tennessee during the Knoxville Campaign.
Prelude to the Battle
Tennessee Secedes from the Union
On June 8, 1861, Tennessee became the last Southern state to secede from the Union. The decision, however, was far from unanimous. In the eastern part of the state, voters defeated a referendum on secession by some 20,000 votes at the polls. Starting an independent secessionist movement, citizens of East Tennessee petitioned the state legislature to form a new state that would remain in the Union. The governor responded by sending military personnel to Knoxville to enforce the statewide vote for secession. Despite attempts to coerce the population, many residents in East Tennessee and Knoxville remained pro-Union throughout the American Civil War.
Tennessee’s Strategic Importance
President Abraham Lincoln considered the liberation of East Tennessee to be of paramount importance. Beyond the moral and political duty to support the loyal citizens of that part of the Union, East Tennessee was strategically valuable. The main railway connecting the Confederate capital at Richmond, Virginia to Chattanooga, Tennessee, and on to the Deep South ran through Knoxville. In addition, East Tennessee farmers produced large amounts of food supplies that could sustain whichever side controlled the area. Despite its strategic importance and being high on the president’s list of priorities, events in other theaters of the war delayed any major Union action in the area until the Army of the Ohio, commanded by Major General Ambrose Burnside, moved to occupy East Tennessee in the summer of 1863.
Federals Occupy Knoxville
By the time Burnside neared Knoxville, events occurring in the Chickamauga Campaign had forced most of the Confederate defenders to move to southern Tennessee, leaving only a token force behind. Burnside’s cavalry reached Knoxville on September 2, almost unopposed. On September 3, citizenry warmly greeted Burnside’s army when marched into Knoxville. With Knoxville occupied, Burnside next captured the Cumberland Gap on September 9, and he turned his attention to clearing the area of any remaining Rebels.
Burnside Advances Toward Chattanooga
Shortly after Burnside secured East Tennessee, Confederate General Braxton Bragg and his Army of Tennessee soundly defeated Major General William Rosecrans and his Army of the Cumberland at the Battle of Chickamauga (September 19–20). Bragg drove Rosecrans’s army out of northern Georgia, back to Chattanooga, Tennessee, and then besieged the city for two months. As the Union situation at Chattanooga worsened, Washington officials ordered Burnside to leave Knoxville and march south to help lift the siege. Burnside moved toward Chattanooga, but skirmishes with Confederate cavalry slowed his advance from Virginia
Bragg Rids Himself of Longstreet
Meanwhile, in southern Tennessee, Bragg recognized that Burnside’s army posed a threat to his investment of Chattanooga. During the siege, relations between Bragg and fellow Confederate General James Longstreet deteriorated because of Longstreet’s criticism of Bragg’s failure to pursue the defeated Federals more aggressively at Chickamauga. Wanting to rid himself of Longstreet, Bragg received approval from Confederate President Jefferson Davis to detach Longstreet from Bragg’s command and to send Longstreet north to deal with Burnside. Bragg planned on Longstreet being able to drive Burnside away, re-capture Knoxville, and return south before Ulysses S. Grant, who had replaced Rosecrans, could attempt a breakout from Chattanooga.
Longstreet Advances and Burnside Withdraws
On November 4, 1863, Longstreet departed from the Chattanooga area on the East Tennessee & Georgia Railroad with a force of about 10,000 infantrymen, supported by about 5,000 cavalry troopers. On November 16, his army engaged Burnside’s army at the Battle of Campbell’s Station and forced the Federals to fall back to their fortifications at Knoxville.
Longstreet Besieges Knoxville
With the Federals safely entrenched in Knoxville, Longstreet besieged the city on November 19. However, Longstreet knew that Bragg could recall him to Chattanooga if Grant threatened Bragg’s investment there. Thus, Longstreet also searched for a weakness in Burnside’s fortifications that he might exploit.
Longstreet Attacks Fort Sanders
Longstreet decided that Fort Sanders, northwest of Knoxville, was the most vulnerable position in Burnside’s defenses. On November 29, Longstreet ordered a surprise attack on the fort, which was protected by a twelve-foot-wide ditch with vertical sides ranging from four to ten feet deep. Crossing the ditch under enemy fire proved impossible, and the Federals easily repulsed the assault in only twenty minutes.
Aftermath of the Battle
The battle resulted in a Union victory.
Confederate losses were heavy. Of roughly 4,000 men engaged in the attack, over 800 were casualties (129 killed, 458 wounded, and 226 captured). The Union lost only around 20 men.
Before Longstreet could plan another assault, he received news of Bragg’s defeat at Missionary Ridge (November 25, 1863) and of the Confederate retreat into Georgia. Bragg ordered Longstreet to abandon his siege at Knoxville and rejoin the Army of Tennessee in Georgia.
Grant, however, had sent a relief force toward Knoxville, commanded by William T. Sherman. Upon learning that Sherman’s departure, Bragg changed his mind and ordered Longstreet to stay at Knoxville as long as possible to prevent Sherman from returning to Georgia. Longstreet held out until December 4, when he lifted the siege of Knoxville and marched his army northeast.